In the manufacturing process for PLED (Polymer Light-Emitting Diode), usually the light emitting pixels of three primary colors red, green, and blue are formed by inkjet printing technology. That is, absorb a substrate which has been ITO (Indium Tin Oxide) patterned in advance on a printing base, and spray a hole-transport material and a solution of light emitting materials of three colors red, green and blue in sub-pixel recesses on the substrate, to form light emitting pixels of three primary colors red, green and blue. However, the drying atmospheres of the edge pixels and center pixels of the substrate are inconsistent from each other, which results in the drying rate of the edge pixels being larger than the drying rate of the center pixels, leads to non-uniform thickness of the whole pixel thin film of the substrate, so that largely affects the display effect of the PLED.
The solution in the prior art usually is providing a test area at periphery of a display area of the substrate, which display area is an area for forming the pixels; after that, when the inkjet printing is performed, the test area is firstly inkjet printed, to form a solution atmosphere around the display area, and then the display area is inkjet printed. By means of the solvent atmosphere formed, the drying rate of the edge pixels and the drying rate of the center pixels of the display area can be maintained consistent, which in turn ensures that the uniform thickness of the pixel thin film in the display area. However, when the size of the substrate is fixed, providing a test area at the periphery of the display area of the substrate reduces the area of the display area. Besides, the test area cannot be used for displaying image, which therefore increases the bezel width of the liquid crystal display panel.